DTDownload started out as a wrapper around NSURLConnection when I needed resumable file downloads for iCatalog. It has since grown into several parts. For file and image caching you can use DTDownloadCache, for queueing up a large number of downloads use DTDownloadQueue.

Open Source Software

This component is available as open source software, covered by a BSD 2-clause license. As such you can use it for free in your apps, even commercially. But you have to mention that your software makes use of this component inside your app.

You can purchase a “Non-Attribution License” via the Parts Store button so that you don’t have to attribute. This license costs 75 Euros.